DominikStefancik/Add Resources section

[DominikStefancik]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/nestjs/docs.nestjs.com/blob/master/CONTRIBUTING.md

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: 519
Issue Link: #519

What is the new behavior?

New section Resources has been added to the header.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[kamilmysliwiec]

Thank you for your contribution!

Unfortunately, we don't plan to add resources page that would consist of articles, videos, and recommended courses because this wouldn't scale over time. If we ever create a resources page, this will be rather a place for some recommended 3rd-party libraries (but for that, we have Recipes section in the docs, exclusively for each package so I'm not sure about it yet)